Fix the problem of not enough merged dtb size

The dtc has suffix compression for string, ex. "a_string", "string"
and "ing", these strings could share a same string in dtb
string table. libufdt assumes the merged dtb size shouldn't larger
than the summary size of base and overlay dtb, and doesn't
apply the same compression.

The patch add a test case for this case and fix the problem.

Bug: 35255584
Test: tests/run_tests.sh
Change-Id: I6bac1e2823ca90dbdb852452544c41ab040a5ccc

3 files changed, 27 insertions, 0 deletions

diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index 4513950..ea3e5ba 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -69,6 +69,9 @@ main() {
   run_test_case \
     "empty_overlay" \
     "Run test about overlaying with empty base and overlay dt"
+  run_test_case \
+    "suffix_compress" \
+    "Run test about string suffix compression"
   )
 
   if [ $? -ne 0 ]; then
diff --git a/tests/testdata/suffix_compress-base.dts b/tests/testdata/suffix_compress-base.dts
new file mode 100644
index 0000000..1c51284
--- /dev/null
+++ b/tests/testdata/suffix_compress-base.dts
@@ -0,0 +1,18 @@
+/dts-v1/;
+
+/ {
+  /* these name could be suffix compressed in dtb after compiled */
+  longlonglonglonglonglonglonglonglonglonglonglongname: longlonglonglonglonglonglonglonglonglonglonglongname {};
+  longlonglonglonglonglonglonglonglonglonglongname: longlonglonglonglonglonglonglonglonglonglongname {};
+  longlonglonglonglonglonglonglonglonglongname: longlonglonglonglonglonglonglonglonglongname {};
+  longlonglonglonglonglonglonglonglongname: longlonglonglonglonglonglonglonglongname {};
+  longlonglonglonglonglonglonglongname: longlonglonglonglonglonglonglongname {};
+  longlonglonglonglonglonglongname: longlonglonglonglonglonglongname {};
+  longlonglonglonglonglongname: longlonglonglonglonglongname {};
+  longlonglonglonglongname: longlonglonglonglongname {};
+  longlonglonglongname: longlonglonglongname {};
+  longlonglongname: longlonglongname {};
+  longlongname: longlongname {};
+  longname: longname {};
+};
+
diff --git a/tests/testdata/suffix_compress-overlay.dts b/tests/testdata/suffix_compress-overlay.dts
new file mode 100644
index 0000000..382e376
--- /dev/null
+++ b/tests/testdata/suffix_compress-overlay.dts
@@ -0,0 +1,6 @@
+/dts-v1/;
+/plugin/;
+
+&longname {
+  x {};
+};